A serial killer already linked to the murders of four Long Island area Craigslist prostitutes is so intimately familiar with police investigation techniques that law enforcement officials are now openly speculating he may be one of their own.

The absolutely chilling admission arrives in the wake of several untraceable calls made to members of the victims' families, during which a "calm and bland" voice told one victim's twin sister numerous vulgar things about the crime and expressed anger about women who worked as prostitutes.

All calls were kept under three minutes and were made from disposable cellphones, so as to thwart call tracing techniques presently employed by New York authorities. The full content of those calls was not released to the public as part of an effort to discourage copycats and false confessions.

"He is a guy who is aware of how we utilize technology," one investigator said [in an interview with the New York Times]. "Frankly, people are thinking maybe he could be a cop" - either one still in law enforcement or one who has moved on.

"Without question, this guy is smart, this guy is not a dope," the investigator continued. "It's a guy who thinks about things."

What's especially frightening about this case is that, while the killer is admittedly very familiar with how police investigate these heinous crimes, the tactics authorities have revealed to the public thus far are ones an everyday citizen could easily pick up after watching an episode of C.S.I. or that show with the obvious parallels, Dexter.

Keeping calls under three minutes to thwart phone traces; calls made to the victims' families from disposable cellphones; calls made from high traffic areas like Madison Square Garden to foil surveillance attempts—these are all techniques that I've learned about through the years simply by watching summer blockbuster movies or Showtime dramas. The evidence presented here seems to indicate they actually work in the real world.

Admittedly, authorities have not revealed everything they know about this case, so there could be even more, expert-level techniques that this killer could is employing to keep the police off his tracks. This makes everything even more frightening!

To date, efforts to corner or even track the rough location of the Long Island serial killer's calls have been ineffective. No suspect has been identified nor have any pesons of interest been floated to the public. What we do know, thanks to the aforementioned phone calls, is that the killer has it in for prostitutes and is incredibly put out by their way of life.

This is all very unsettling, as serial killer cases always are, but with the tools and media available to sickos today, can anyone really claim to be surprised? [NYT]